Tablet forming machines



Aug. 12, 1969 w. RLKIBBE TABLET FORMING MACHINES 2 Sheets-Sheet 1 FiledSept. 22, 1967 Aug. 12, 1969 w. R. KIBBE 3,460,487

TABLET FORMING MACHINES Filed Sept. 22, 1967 2 Sheets-Sheet 2 UnitedStates Patent 3,460,487 TABLET FORMING MACHINES Walter R. Kibbe,Philadelphia, Pa., assignor to Sterling Drug Inc., New York, N.Y., acorporation of Delaware Filed Sept. 22, 1967, Ser. No. 670,523 Int. Cl.B29c 3/04; B30b 11/04, 7/00 US. Cl. 107-17 Claims ABSTRACT OF THEDISCLOSURE A tablet forming machine utilizing finely comminutedpowder-like material through the use of a new and improved agitatingmechanism for the powder as it is fed from a hopper to the dies, thusinsuring greater uniformity of the powder entering the dies, and bettercompacting of finer powder than heretofore possible. The agitating isperformed by one or more oscillating elements which are mounted in fixedposition with relation to a feeding device leading from the hopper tothe dies, and having means struck by the upper punches as they pass thefeeding station, the present invention providing for improved agitatingand compacting of the powder and also providing for recirculation ofexcess powder around the entire rotary head back to the originalposition at the feeding device.

Prior art US. Patent 3,016,027, July 9, 1962 (Edgar et al.) which showsa mechanical type feeder requiring separate drives and having somerotary agitation.

US. Patent 3,016,572, Jan. 16, 1962 (Stoot) showing a mechanical typefeeder with a built-in drive and showing rotary agitation, and

US. Patent 3,029,470, Apr. 17, 1962 (Frank) showing a vibratory typefeeder having no agitation.

This invention relates to a tablet making machine, and the principalobject of the invention resides in the provision of new and improvedagitating means for the powder which is directed from a hopper thereforto a series of pockets containing dies in a rotary head, the powder thenbeing compacted as for instance by punches in increasing pressurearrangement as the head rotates, the finished tablets being ejectedprior to a complete revolution to repeat the cycle.

In the past it has been found impossible to satisfactorily form tabletsfrom powders under a certain degree of fineness. This invention, byproviding an improved agitating means for the powder prior to entry intothe dies, provides for the successful manufacture of tablets from finepowders to the end that the speed of dissolution of these tablets influid is increased.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which:

FIG. 1 is a view in side elevation illustrating the invention;

FIG. 2 is a plan view thereof with parts omitted;

FIG. 3 is a section on line 33 of FIG. 2, and

FIG. 4 is a section on line 44 of FIG. 2.

In illustrating the present invention, it is pointed out that the basisof the machine in which it is used is of more or less conventionaldesign embodying certain drives, motors, etc. as are conventional andwell known in the art and as exemplified by the United States patentscited, i.e., U.S. Patents 3,016,027; 3,016,572; 3,029,470. In thepresent case a rotary head 10 is provided, this head being of courseproperly mounted and driven. The head is provided with a die tablegenerally indicated at 12, this die 3,460,487 Patented Aug. 12, 1969table having a horizontal surface provided with vertical pockets inwhich die bores are provided, preferably with inserted die members asindicated at 14.. There is an annular series of upper punches generallyindicated at 16 and an annular series of similar lower punches generallyindicated at 18. These punches rotate with the head and dies. Powderenters for instance in the area at 20, see FIG. 1, at a feeding station,fills the dies, and thereafter cam means (not shown) move the punchestoward each other to compress tablets in the dies. Usually a tablet iscompletely compressed to the degree desired in just less than a singlerevolution of the rotary head, whereupon it is ejected and the punchesretracted to open position once more for the feeding station. Somemachine of the prior art are designed to produce two or more tabletsduring a single rotation but the present invention. is applicable tosuch a machine as well as to a single revolution type.

The punches are vertically arranged in opposite pairs to operate on avertical axis in the die bores, which receive their powder as forinstance from a hopper 22 of any known description mounted in anydesired way as for instance on a support 24, see FIG. 1, the powderdescending into a feed chute spout 26 and descending by gravity througha feed shoe conventionally shown at 28 for instance in FIG. 2. This feedshoe is provided with an opening which receives the powder from thelower end of the feed shoe spout 26 and it is provided with means foradjusting the flow, this being a plate variably closing the openingwhich is indicated at 30 by means of a lever 32, the same usually beingprovided with a lock at 34.

This feed shoe and feed spout may be conveniently mounted on the feederframe as at 36 so that it can be removed for cleaning, etc. The feederdevice, feeder frame, feed shoe, etc. are mounted in fixed relation sothat the powder will be received on the die table in the area of thedies as it rotates thereunder.

The powder agitating means forming the present invention to be describedis conveniently mounted in fixed relation on the supporting feeder frame36, the latter being conveniently mounted in fixed position on arms 38mounted on studs 40, the latter finding a support where desired on theframework of the machine in fixed relation with respect thereto. Thesupporting frame 36 is generally open as clearly shown in FIG. 2 whereit is provided with a series of oscillating agitator elements generallyindicated at 42, 44, 46. These are journaled as for instance at 48, 48in the side walls of the frame 36 transverse to the path of travel ofthe dies, and are generally held in upright position as shown forinstance in FIG. 4 by a retracting spring 50 having an end secured to apart of frame 36. This also mounts an adjustable stop 52 which has anoperative end at 54, this stop being conveniently mounted for axialadjustment by any desired means. There is also a stroke adjustmentmember 56 having a slot 58 for adjustment thereof, see FIG. 3. Thespring, stop, and stroke adjustment can all be mounted on member 60which is a part of frame 36.

Each agitating element has an upright arm 62 rising well above the frame36 and each upright arm 62 has a slot 64 therein adjustably mounting anadjustable striker bar 66 by means of a nut 68 located in a slot 70. Bymeans of the two slots 62 and 70 the striker bar can be adjusted up anddown and in and out so as to vary the degree with which it is struck bythe passing of punch 16, see particularly FIG. 1. The agitating elementsmay be made in finger or comb shape as shown best in FIG. 3 at 82.

Each frame member 60 is provided with an opening 72 in its lower edgefor the passage of excess powder as for instance from right to left inFIG. 2, this excess powder then moving into the area at 74 againstscraper bar 76 which moves it inwardly into the areas '78 on therotating die table where it is recirculated 360 back to the agitatingmechanism for disposition into the dies as for instance in the area at80 as the die pockets pass thereunder.

The powder descends by gravity as explained above in the area at 30 inthe feed shoe, being deposited on the rotating die table and enteringinto the die bores as they pass under the feed shoe. As the powderreaches the die table, it is agitated by the agitating element 42 as thecorresponding upper punch 16 strikes the corresponding adjustablestriker bar 66. The degree of agitation depends upon the adjustment ofthe striker bar.

As the punches advance they strike the striker bars one after the other.The agitating element 42 is the first to be moved in a counterclockwisedirection as in FIG. 4, giving the powder a kick in the directionopposite to the direction of motion of the die table. Spring 50 thenbrings the agitating member back to its original position,

FIG. 4, and the powder passes through the corresponding opening 72 intothe area between the agitating element 42 and the agitating element 44.The latter once more agitates the powder which of course again moves ina clockwise direction, teeth 82 and through opening 72, into an areawhere it is again acted upon by agitating element 46. After this itpasses into the area 74 as described and is recirculated.

A scraper at 84 acts to direct the recirculated powder into the area at80 and at 86 a table knockoff bar can be provided or this bar can beprovided at any point where the tablets become completed and ejectedupwardly onto the die table, as usual and well known in the art.

It is believed it Will be appreciated that this invention provides for arelatively high degree of agitation of the powder and that this actionis adjustable. Each of the three agitating elements shown can beadjusted to a different degree if this should be found to beadvantageous. The invention is not limited to three agitator members asin some cases one may be enough or even more than three may be found tobe desirable, depending in part upon the nature of the powder and itsdegree of comminution.

By the use of this agitating device, tablets of a very high degree offineness may be compacted so that a smaller tablet of the sameeffectiveness as before in a larger tablet results; the compression maybe increased to make a smaller tablet; and the solubility of the tabletis greatly increased because of the increased fineness of the powder.

What is claimed is:

1. A tablet forming machine of the type including a rotary head havingcircumferentially spaced forming dies therein, a filling device fordepositing material to be formed into tablets onto said head in the areaof the dies, and means on the head aligned with the dies to compact thematerial therein as the head rotates relative to the filling device,

means to agitate the material over the dies as the latter receive thesame, said agitating means including a movable member having a cyclicmotion at least in part generally opposed to the direction of motion ofthe rotary head and means including an operative part of the machineimpinging upon the movable member to move it.

2. The tablet forming machine of claim 1 wherein the operative machineparts comprises a punch for compacting, and including means on themovable member in the path of the punch for impingement thereby to movethe member.

3. The tablet forming machine of claim 1 wherein the operative machinepart comprises a punch for compacting, and including means on themovable member in the path of the punch for impingement thereby to movethe member in one direction, and means to return the movable member to anormal position.

4. The tablet forming machine of claim 1 wherein the operative machinepart comprises a punch for compacting, and including means on themovable member in the path of the punch for impingement thereby to movethe member in one direction, and means to return the movable member to anormal position, said member being oscillatable on a generallyhorizontal axis.

5. The tablet forming machine of claim 1 including means to vary thedegree of movement of said member.

6. The tablet forming machine of claim 1 wherein the operative machinepart comprises a punch for compacting, and including means on themovable member in the path of the punch for impingement thereby to movethe member, the means on the movable member being adjustable to vary thedegree of movement of the member.

7. A tablet forming machine of the type including a rotary head havingcircumferentially spaced forming dies therein, a filling device fordepositing material to be formed into tablets onto said head in the areaof the dies, means on the head aligned with the dies to compact thematerial therein as the head rotates relative to the filling device, anoscillatory element to agitate the material, and element being locatedbetween the filling device and the rotating head in the path of thedies, and means forming a part of the compacting means constructed andarranged to periodically cause the oscillatory element to be actuated.

8. The tablet forming machine of claim 7 including means pivotallymounting the oscillatory element on an axis generally normal to themotion of the dies, so that a part of the oscillatory motion of theelement tends to cause at least some of the material to move temporarilycontrary to the motion of the head.

9. The tablet forming machine of claim 1 wherein the compacting meansincludes a series of said operative machine parts, each including anaxial punch cooperating with the dies, and means for actuating theoscillatory element, the last-named means being in the path of thepunches, so that agitation takes place as the respective dies pass thefilling device.

10. The tablet forming machine of claim 7 including an arm on theoscillatory element and a relatively adjustable striker member on thearm, the striker member being in the path of the compacting means andbeing impinged upon thereby.

References Cited UNITED STATES PATENTS 1,124,567 1/1915 Wickstrom.

2,096,442 10/1937 Wittmann 259-128 2,173,715 9/1939 Geldhof 259101 XR2,644,677 7/1953 Simon 25910l 2,984,267 5/1961 Gross.

3,000,331 9/1961 Frank 107-17 XR 3,029,470 4/1962 Frank 107--17 XRWILLIAM I. PRICE, Primary Examiner A. O. HENDERSON, Assistant ExaminerUNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,460,487 August 12, 1969 Walter R. Kibbe It is certified that error appearsin the above identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1 line 33, S toot" should read Stott Column 3, line 67 "parts"should read part Column 4, line 30 "and" should read said Signed andsealed this 27th day of October 1970 (SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

